1. Field of the Invention
This invention concerns opening of blocks of tobacco which have been packed in cases, bales or hogsheads. Such blocks have laminations or strata and successive layers or slices taken along such strata are removed and are then fed to a conditioning process. (There is an alternative procedure in which slices are taken at right angles to the strata, which does not concern this invention.). In particular the invention thus concerns the means and method for dividing off the slices parallel with the strata.
2. History of the Related Art
Patent applications EPO 0095866 and EPO 0159836 disclose examples of prior art in this field.
When dividing a slice from the package it is desirable to divide it at a boundary between natural strata in the package to obtain a clean division. In practice these strata are not flat planes, but are generally convex due to the way the block has been formed (or concave if the block has been inverted). In some cases the strata can be sloping if the filling of a case containing the block is biased to one side or one end.
Existing systems for separating such slices typically use a two pronged fork (as fitted to a fork lift truck), which is forced into the block. Because these prongs are rigid, blunt ended and moving on a fixed path they tend to cut or tear through the laminations, degrading the leaves in the lamina. And then when the slice is separated from the main package there is an untidy cleavage of interlocking lamina, which hang below the prongs.
It is very difficult to make a prong or blade which is sufficiently compliant to follow the contour of a strata in all three dimensions, and if two or more prongs are used, it is also difficult in practice to enter these between the same strata.